mybatisplus使用Caffeine作为mapper层二级缓存

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引入Caffeine

<dependency>
            <groupId>com.github.ben-manes.caffeine</groupId>
            <artifactId>caffeine</artifactId>
            <version>2.9.0</version>
        </dependency>

封装好的工具类：

package com.ciih.authcenter.client.util;

import com.github.benmanes.caffeine.cache.Cache;
import com.github.benmanes.caffeine.cache.Caffeine;
import org.springframework.stereotype.Component;

import java.util.concurrent.TimeUnit;
import java.util.function.Function;

/**
 * 缓存之王
 *
 * @author Lenovo
 */
@Component
public class CaffeineService {

    private Cache<Object, Object> cache;

    public CaffeineService() {
        this.cache = Caffeine.newBuilder()
                //过期策略:一分钟没有读取,则过期删除
                .expireAfterWrite(1, TimeUnit.MINUTES)
                //允许容量100个,超过自动删除
                .maximumSize(100)
                .build();
    }

    /**
     * 存储K-V
     *
     * @param key
     * @param value
     * @return
     */
    public Object put(Object key, Object value) {
        cache.put(key, value);
        return key;
    }

    /**
     * 获取K-V
     *
     * @param key
     * @return
     */
    public Object getIfPresent(Object key) {
        return cache.getIfPresent(key);
    }

    public Object get(Object key, Function<Object, Object> function) {
        return cache.get(key, function);
    }

    public void remove(Object key) {
        cache.invalidate(key);
    }

    public void cleanUp() {
        cache.cleanUp();
    }

    public long estimatedSize() {
        return cache.estimatedSize();
    }
}

Mybatis缓存实现类

import cn.hutool.extra.spring.SpringUtil;
import com.ciih.authcenter.client.util.CaffeineService;
import lombok.extern.slf4j.Slf4j;
import org.apache.ibatis.cache.Cache;

import java.util.concurrent.locks.ReadWriteLock;
import java.util.concurrent.locks.ReentrantReadWriteLock;

/**
 * 二级缓存实现
 *
 * @author Lenovo
 */
@Slf4j
public class MybatisCache implements Cache {

    private CaffeineService caffeineService;

    private final ReadWriteLock readWriteLock = new ReentrantReadWriteLock(true);

    private String id;

    public MybatisCache(final String id) {
        if (id == null) {
            throw new IllegalArgumentException("Cache instances require an ID");
        }
        this.id = id;
    }

    @Override
    public String getId() {
        return this.id;
    }


    @Override
    public void putObject(Object key, Object value) {
        if (caffeineService == null) {
            caffeineService = SpringUtil.getBean(CaffeineService.class);
        }
        if (value != null) {
            caffeineService.put(key, value);
        }
    }

    @Override
    public Object getObject(Object key) {
        if (caffeineService == null) {
            caffeineService = SpringUtil.getBean(CaffeineService.class);
        }
        try {
            if (key != null) {
                return caffeineService.getIfPresent(key);
            }
        } catch (Exception e) {
            log.error("缓存出错 ");
        }
        return null;
    }

    /**
     * As of 3.3.0 this method is only called during a rollback
     * for any previous value that was missing in the cache.
     * This lets any blocking cache to release the lock that
     * may have previously put on the key.
     * A blocking cache puts a lock when a value is null
     * and releases it when the value is back again.
     * This way other threads will wait for the value to be
     * available instead of hitting the database.
     *
     * @param key The key
     * @return Not used
     */
    @Override
    public Object removeObject(Object key) {
        if (caffeineService == null) {
            caffeineService = SpringUtil.getBean(CaffeineService.class);
        }
        caffeineService.remove(key);
        return null;
    }

    /**
     * Clears this cache instance.
     */
    @Override
    public void clear() {
        if (caffeineService == null) {
            caffeineService = SpringUtil.getBean(CaffeineService.class);
        }
        caffeineService.cleanUp();
    }

    /**
     * Optional. This method is not called by the core.
     *
     * @return The number of elements stored in the cache (not its capacity).
     */
    @Override
    public int getSize() {
        if (caffeineService == null) {
            caffeineService = SpringUtil.getBean(CaffeineService.class);
        }
        return (int) caffeineService.estimatedSize();
    }

    /**
     * Optional. As of 3.2.6 this method is no longer called by the core.
     * <p>
     * Any locking needed by the cache must be provided internally by the cache provider.
     *
     * @return A ReadWriteLock
     */
    @Override
    public ReadWriteLock getReadWriteLock() {
        return this.readWriteLock;
    }
}

配置一下Dao接口

@CacheNamespace(implementation= MybatisCache.class,eviction=MybatisCache.class)
public interface SchoolDao extends EasyBaseMapper<School> {
    
}

配置xml

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE mapper PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN" "http://mybatis.org/dtd/mybatis-3-mapper.dtd">
<mapper namespace="com.ciih.authcenter.client.dao.SchoolDao">
    <cache-ref namespace="com.ciih.authcenter.client.dao.SchoolDao"/>

</mapper>